A Brief Lesson:
I'm frequently asked "Will this phone work for me?". If you have an old fashioned "Land Line", technically called POTS, then the answer is "yes", you have nothing to worry about. Your rotary phone will work just fine for you. If you have DSL internet over your POTS line, then you will need to add a DSL filter to your phone line. These are readily available at any hardware or phone store. If you have digital "VOIP" service, then the answer is "maybe". When you have digital phone service, your service provider will install an ATA (Analog Telephone Adapter) in your home to divert your home phone wiring from the phone company to the digital line. This ATA takes all your phone calls made in your home, converts them to digital, then sends them down the cable. Most of these ATA devices have issues with phones dialing in pulses (rotary). Sometimes they work, sometimes they don't. Sometimes they'll work, but only if the pulse rate is exactly to specification. The most reliable way to know if a rotary phone will work for you is to get your hands on one and plug it in and try dialing out. If it dials out, you're set. If it doesn't dial out, then you have to think of a Plan B.
What are your options?
Should you determine that you're unable to dial out, there are Options.
About Magic Jack:
Magic Jack has a couple of ways to be used. If you use the Magic Jack through the USB port of your computer, then you will not be able to dial out and your ringer will not work. The ringer on vintage telephones relies on a ringing voltage of around 100 volts, you're certainly not going to get that from your computer's USB port! If you use the 120volt plug in that comes with your kit, then your ringer will work, but you still won't be able to dial out.